These are external links and will open in a new window. Around the world, 91 million people are on dating websites and apps. Finding "the one" among them may seem daunting - but some tips based on scientific research might help, writes Dr Xand van Tulleken. Some people enjoy being single but, perhaps because I'm an identical twin, for Sitti s secrets online dating it's purgatory. Nonetheless I found myself single having - wrongly I suspect - prioritised work and travel for too long.
So for the BBC's Horizon, I decided to see if using a scientific approach on dating sites and apps could help boost my chances of finding a match.
My first problem was getting noticed. For me, writing a dating profile is the hardest and most unpleasant part of online dating - the idea of having to endure the kind of dreadful introspection and accompanying self-recriminations that would be involved in coming up with a brief description of myself was extremely unpleasant.
Added to that, I would also have to describe my "ideal partner" in some way and this has always seemed like an unappealing and vaguely sexist exercise in optimism and imagination. So I took advice from a scientist at Queen Mary University, Prof Khalid Khan, who has reviewed dozens of scientific research papers on attraction and online dating. His work was undertaken not out of pure scientific curiosity but rather to help a friend of his get a girlfriend after repeated failures.
It seemed testament to a very strong friendship to me - the paper he produced was the result of a comprehensive Sitti s secrets online dating of vast amounts of data. His research made clear that some profiles work better than others and, into the bargain, his friend was now happily loved-up thanks to his advice.
Do you know the secret to getting a date online? Take the scientific test to see if you can build the perfect dating profile. Studies have shown that profiles with this balance receive the most replies because people have more confidence to drop you a line. This seemed manageable to me. But he had other findings - women are apparently Sitti s secrets online dating attracted to men who demonstrate courage, bravery and a willingness to take risks rather than altruism and kindness.
So much for hoping that my medical career helping people was going to be an asset.
He also advised that if you want to make people think you're funny, you have to show them not tell them. Much easier said that done. And choose a Sitti s secrets online dating that starts with a letter higher in the alphabet.
People seem to subconsciously match earlier initials with academic and professional success. I'd have to stop being Xand and go back to being Alex for a while. These tips were, surprisingly, extremely helpful. Don't get me wrong - writing a profile is a miserable business, but I had a few things to aim for that helped break my writer's block and pen something that I hoped was half-decent.
With my out there, the next problem became clear. Who should I go on a date with? With a seemingly endless pick of potential dates online, mathematician Hannah Fry showed me a strategy to try. The Optimal Stopping Theory is a method that can help us arrive at the best option when sifting through many choices one after another. I had set aside time to look at women's profiles on Tinder, swiping left to reject or right to like them.
My aim was to swipe right just once, to go on the best possible date. If I picked one of the first people I saw, I could miss out on someone better later on. But if I left it too late, I might be left with Miss Wrong. I should then choose the next person that's better than all the previous ones. I won't lie - it wasn't easy rejecting 37 women, some of whom looked pretty great.
But I stuck to the rules and made contact with the next best one. And we had a nice date. If I applied this theory to all my dates or relationships, I can start to see it makes a lot of sense.
The maths of this is spectacularly complicated, but we've probably evolved to apply a similar kind of principle ourselves. Have fun and learn things with roughly the first third of the potential relationships you could ever embark on.
Then, when you have a fairly good idea of what's out there and what you're after, settle down with the next best person to come along.